Refrigerating or cooling apparatus.



G. HILDEBRANDT.

BEFRIGEBATING 0R COOLING APPARATUS.

APPLICATION FILED DEO.20,1907.

963,555, Patented July 5, 1910.

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G, HILDEBRANDT. REPBIGERATING 0R 000mm APPARATUS.

APPLICATION FILED DEG. 20,1907.

Patented July 5,1910.

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min-ran STATES PATENr-iormon L imcntcd an Improvement in Refrigerating ll'ith reference GOTTHOLD HILDEBRANDT, OF BERLIN, GERMANY.

REFRIGERATING OB COOLING APPABiATUS.

963,555. Specification of Letters P ent. Patent-ed July 5, 1910.

Application filed December 20. 1907. Serial No. 402.356. i

I all whom it may concern: are central longitudinal sections illustrat Be itknown that I, (lo'i'rnou) HtLnE- ing modified or ditlerentforms of a refrigaeaxor, a subject of the Emperor of Gere'rating or cooling apparatus made in acman v. residing at Berlin, Germany, have cordance with my )resent invention.

) first to Figs. 1 and 2, air or Cooling Apparatus, of which the followexpanded from the high-pressure pipe a ing is aspecitication. through the valve 7/ and thus cooled is ad- This invention relates to refrigerating or mitted by way of a liquid-separator 0 into a cooling and final liquefaction of gases by closed counter-current apparatus or refr'ig -s5 means of the expansion of compressed gases erator dwhere it cools the compressed an and apparatus therefor, and has particular admitted in the opposite direction, so that, reference to an apparatus whereby gases the air thus cooled arrives at the expansion with low boiling points, such. for example, valve I) with it gradually decreasing temas atmospheric air, can be utilized for this perature. In such apparatus, which may be purpose as etliciently as can gases with taken as typical of that. hitherto used, the. higher-boiling points such, for example as important cooling action of the. expanding ammonia, carbonic acid or the like. gas on the outletnozzle itself has been negllitherto owing to the small heat-capacity lected, and importance attached chiefly to of air and other gases having low boiling the cooling effect of the expanded gas in points, they have not been able to be used the cormter-current apparatus alone. It is with economy for the purposes of refrigerneglect of this cooling action on the nozzle ating and hquefying gases owingto the.- itself which accounts in great measure for fact that the compression cylinder had necthe ditlereuce between the theoretical and essarily to be very large compared to that practical results abovenientioned'. so used with, say, ammonia. At the moment of the expansion of the According to this: invention the gas is highly compressed air, heat. is absorbed, for compressed and cooled in any well known the gas itself being cooled tends to absorb way, but instead of then being allowed to heat from the nearest heat-containin body, expand through a regulating valve directly that is the expansion valve or the out etnozinto a refrigerator or counter-current" zle, which in its turn draws heat from the apparatus, it is first caused to eflect a presurrounding, insulatingmaterial and from liminary cooling of the compressed gas tiowthe adjoining metal-supply pipe, and even ing toward the valve. from the refrigerator to which that pipe is As is well known, theoretical calculations connected. This action necessarily lenders give a much greater fall of temperature due the temperature produced by the expansion to the expansion of compressed air than can of the compressed gas considerably higher be obtained in practice, that is to say, the than it should be. It may be said that the expanded air from cold air com )ression maexpansion of the compressed gas results in chines is considerably warmer than it ought two distinct cooling effects, one. that. proto he in accordance with theory. For this duced in the surrounding air at the moment; reason the use of air and other gases with of expansion which may be termed the rilow boiling points for the purposes of remary effect. and the other that produced in frigerating or cooling and hquefying gas s the. regulating valve or in the expansion 1102- has been largely abandoned in favor of re" zle, which may be termed the secondary irigerating compression machines cmployfi tf In apparatus hitherto used, the secing gases such as ammonia, carbonic acid. ondary effect has not contributed to the end sulfurous acid, etc. Or when for special in view. for example refrigerating or coolpurposes air or' other low boiling point gas in or liquefying another gas-but has sun- -has been used. the final low cooling or ply been wasted by conduction and radtaliquefying has been only attained by thccon-' tion in the apparatus.

sumption of a greater amount of energy. F r fficient. working it is necessary to in the drawing, Figure 1 is a central lonprevent the lowering of temperature due to gitudiual cross section and Fig. 2 is a simithe secondary efi'ect from lwcomi-ng distriblar view showing diagran-tmatically, fOllllS uted over large areas of the material or 110.

of refrigerating or cooling apparatus which substance cooled. That is to say, this secare well-known in the arL Figs. 3, 4 and 5 ondary efiect must be localized in order to duced y the secondary effect be distributed over large areas, then although it may be 5 possible to cool the water, it is impossible to freeze it. in a sutliciently shoit time, as owing to conduction and radiation, the losses incrcase with the increase of time occupied by the process. The efficiency of the process is quite different when the cold produced by the secondary effect is concentrated in a small space and caused to act first on the freshly supplied compressed air. In that case the supply of water nearest to the source of cold is very quickly frozen before the intensity of the action is lost In order to liquefy gases with low boiling points in a reliable manner, the cold produced by the expansion should be so concentrated that, for example, in the liquefaction of atmospheric air, the temperature should be at any rate as low as 14:0 C. If the temperature be even a few degrees higher, it is insufficient for obtainin the result desired. But on the other hand, if this low temperature be obtained even if it be but temporarily so as to effect at one time but a very small quantity of gas in a very small space, it is possible to liquefy in consecutive steps and to accumulate any desired quantity of air, while otherwise the liquefaction either does nottake place at all, or takes place only after a long time, durin which a large proportion of the piping an apparatus have been cooled in a useles manner to a very low temperature.

The present invention consists, therefore, in localizing or concentrating the secondary cooling effect produced in the expansion nozzle, so that it acts in conjunction with the primary cooling effectproduced in the gas itself. For this purpose the gas at the moinent of expansion is caused to act upon a small hollow body such, for example, as a I small coiled pipe 0 which, shown in Figs. 3, 4t and 6, surrounds the expansion valve or an-outlet nozzle so closely that the gases escaping inust first come into contact with itbefere they are admitted into counterv current apparatus. The pipe bringing the supply of compressed air is connected to this low cooling coil c instead of being joined directly to the expansion valve b. The coil 6 thus placed is subjected to both the primary and secondary cooling effects of the expanding gas, and owing to thisdoubleinfluence the freshly admitted compressedgas duced.

, passing from the same into the vessel i form ings loop I: therein and passing upwardly passing through the coil is cooled more en ergetically than by methods hitherto known. The smaller a-ndmore compact the arrangement of the low coolin coil. the more sudden and lower is the fall of temperature ob- 7 tained, and the less the possible loss by radiation.

The expanded gas which has thus cooled the coil 6 may then pass by way of a refrigerator or a counter-current apparatus to 7 other compressed gas or to other substances such as brine, etc. which it may be desired to cool or to use for cooling purpose.-, and the whole cooling process may be divided into stages of which the first is 5g represented by that which takes )laoe in the above described low cooling coif c, and the I second by a repetition of similar apparatus 1 or by the counter-currentapparatus. This idea of cooling in stages may be further 55 developed by dividing the, counter-current apparatus itself into separate stages or sections as, for exam le, in the manner illustrated in Fig. 5. ne section is formed by the coil 0 arranged as previously described to with reference to Fig. 3-, and another by the coil f situated in the lower part of the casing. These two sections are connected by a supply pipe 9 which is of comparatively small cross section so that the losses through conduction along the metal ipe are very small. The expanded gas first impinges upon the coil 0 and then passes down the central space around the small pipe 9 and enters the annular space in the lower casing which contains the coil From the upper part of this space it enters the coils d of the counter-current apparatus proper.

The arrangement shown in Fig. 4 illustrates an apparatus suitable for the manufacture of ice or the cooling of brine, the low cooling coil 0 3l'1tll\ '0d between the countercurrent pipe (I and the expansion valve Z1 having the etfect of producing a greater cooling of the casing which transmits the cold to the liquid by freezing, the time of freezing being therefore considerably re- As will be seen by reference to the draw ing. the apparatus constructed in accordance with my present invention may comprise a vessel having a sin le compartment as indicated in Fi m. 3 an 4, or two compartments as indicated in Fig. 5.

Referring particularly to Fig. 3, the counter current coil indicated at h surrounds the vessel 2' and en ers the same at anv suitable point as indicated at 2". The inlet coil d for the compressed air is preferably made concentric with this counter current coil l1 and surrounding the valve 1) in the outer inlet coil e and the inner inlet. coil (1 which latter leads to the inlet orifice of the valve 11,

the valve 2') being provided with apertures Z in such a position that the expanding gas as the same passes through and escapes from the valve, impinges against the outer surface of both the coils a and e.

A somewhat similar structure is shown in Fig. 3, with the exceptions that the valve 6 is inverted and the counter current tube is a straight pipe m instead of a coil, necessitat ing of course an inlet connection pipe a of the same shape; the valve 5 in both instances being contained within the compartment formed by the walls of the vessel.

Referring to Fig. 5, the vessel 1' is provided with two compartments indicated respectively at 0 and 1), having a dividing wall 1' in which there is a centrally disposed apertureto receive one end of the tube 9 which extends therefrom to a point adj acent to the opposite end of the compartment 2) as hereinbefore described. In the construction. shown in this figure, the inlet pipe (Z is arranged in a double coil which extends through the convolutions of the counter current coil it, closely surrounding the walls of the compartment 0 and these inlet coils (Z enter the compartment go through the connection therewith for the end of the counter current coil. h preferably at a point adjacent to the partition wall 7.

The inlet tube (Z extends through the compartment p in a double coil indicated at f to a point adjacent to the end opposite the partition wall 7 at which point the coils f are united as indicated at s in a pipe or tube indicated at t, which pipe 6 extends through the tube 9 into the compartment 0 and closely surrounds the valve 6 in the coils e and a in exactly the same relationship as those hereinbefore described in connection with Fig. 3.

In the use of the apparatus shown in Fig. 5, the compressed air or other gas is sup plied to the pipes or double coils (Z passing through the same within the counter current coil h, passing thence through the double coil f to the pipe 25 and thence through the coils c and a to the valve 5 where the gas is expanded, it being liberated to pass through the valve Z) and in so doing esci es through the apertures Z in the walls 0 the valve, impinging on the outer surface of both coils e and a, the liquefied portions of the gas passing by way of the tube 9 to the compartment p and the remaining gaseous portions thereof escaping by way of the counter current coil h to the atmosphere or a receptacle provided therefor.

It will be noted by reference to Fig. 1 that the compressed air after being admitted to and passing through the valve 5 or so much thereof as is still in the vapor form passes directly to the counter current coil and does not impinge previously to so doing on any part of the inlet pipe for the compressed air, whereas in Fig. 2, after passing through the valve 5, the compressed air is conveyed to the tank 0 from which so much of the compressed air as is still in a gaseous condition, passes from the tank a to the counter current cell.

lVhat I do claim, and desire to secure by Letters Patent, is

1. In an apparatus for refrigerating or cooling by means of the expansion of COIU- pressed gases, the combination with a regulating valve or expansion nozzle, of sepa rate coil sections 6 f, a pipe of relatively small cross section connecting the said coils e f, and a casing having separate compartments in which the said separate coil sections are placed, one of said coils surrounding the said regulating valve or expansion nozzle and there being provided a means of communication between the said compartments and through which the expanded gas flows.

2. An apparatus for refrigerating or cooling by means of the expansion of compressed gases, comprising a vessel, a valve or expansion nozzle located within the said vessel and being provided with apertures through which the expanded gas escapes after passing through the said valve, an inlet pipe for compressed gas leading to the said valve closely surrounding the same and against the exterior of which double coil the expanded gas impinges after passing through the said valve, and a counter current coil leading from the said vessel.

3. An apparatus for refrigerating or cooling by means of the expansion of compressed gases, comprising a vessel, a wall within the said vessel dividing the same into two compartments, a valve or expansion nozzle located within the first of said compartments and being provided with apertures through which the expanded escapes after passing through the said valve, a coil inlet pipe for compressed gas leading to the said valve closely surrounding the same and against the exterior of which double coil the expanded gas impinges after passing through the said valve anda counter current coil leading from the said vessel.

4. An apparatus for refrigerating or cool ing by means of the expansion of compressed gases, comprising a vessel, a wall within the said vessel dividing the same into two compartments, a valve or expansion nozzle located within the first of said compartments and being provided with apertures through which the expanded gas escapes after passing through the said valve, a tube passing through the said partition wall of the vessel and extending from the same to a point adjacent to the opposite end of the said second compartment, a coil inlet pipe for compressed air surrounding the said tube within. the said second compartment &

extending through the said tube and terminating in a double coil closely surrounding the said valve to Which the said inlet pipe leads, and a counter current coil leading from the said second compartment.

5. An apparatus for refrigerating or cooling by means of the expansion of compressed gases, comprising a vessel, a Wall Within the said vessel dividing the same into two compartments, a valve or expansion nozzle located Within the first of said compartments and being provided with apertures through which the expanded gas escapes after passing through the said valve, a tube passing through the said partition Wall of the vessel and extending from the same to a point adjacent to the opposite end of the said second compartment, a counter current coil leading from the said second compartment and closely surroundin the Wall of the said first compartment, an a double coil inlet pipe extending through the convolutions of the said counter current coil into the said second compartment at a point adjacent to the said partition Wall, the said double coil inlet pipe closely surrounding the said tube and extending to a point adjacent to the opposite end of the said second compartment Where these coils are connected to a common pipe extending through the said tube into the first compartment Where the said pipe is connected to a double coil closely surrounding the said valve and leading thereto.

GOTTHOLD HILDEBRANDT.

Witnesses HENRY HASPER, VOLDEMAR HAUrr. 

